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Wild oats are one of Australia’s most widespread and grass (Bromus spp.) however Brome grass has a costly weeds of dryland cropping systems (Figure 1). It tubular leaf sheath and hairy leaves whereas wild oats infests two thirds of all cereal growing properties in have a rolled leaf sheath with few hairs on the leaves. southern Australia and is ranked second only to annual ryegrass as the most problematic weed Origin and Introduction species (Kirby 2000). Infestations can cause yield losses of greater than 80% in wheat, contaminate Wild oats originated in Asia or the Mediterranean grain and host cereal diseases (Nugent, Storrie & region and were most likely introduced into Australia as Medd 1999). It is estimated wild oats cost Australian a contaminant of small grains (Nugent, Storrie & Medd grain growers in excess of $150 million every year in 1999; Kirby 2000). lost production, cost of control and contamination of grain (Anderson 2003). Distribution
Wild oats are found throughout the winter grain growing regions of Australia. Most wild oat populations (about 80%) contain both A.fatua and A.ludoviciana (Cousens 2003) however Avena fatua is the dominant species in southern Australia, Avena ludoviciana is the dominant species in northern New South Wales and southern Queensland and Avena barbata is found predominantly on roadsides and in non-agricultural areas (Nugent, Storrie & Medd 1999).
BIOLOGY AND ECOLOGY
Wild oats are one of the most competitive grass weeds Figure 1. A mature
Photo: J.D. Dodd and are near equal competitors with wheat. Avena fatua plant Competition with the crop begins soon after emergence with most of the yield loss occurring in the
first 6 weeks. It has been estimated that an infestation KEY POINTS 2 as small as 20 plants/m can cause a yield loss of 10% • Use an integrated weed management (IWM) in a wheat crop yielding 2t/ha (Anderson 2003). program Yield losses are strongly influenced by the density of • Be vigilant with record keeping and paddock the infestation and the vigour of the crop, and are monitoring greatest when the wild oats emerge at the same time • Be aware of the new mode of action groups for as the crop. Wheat yield, tiller number and dry matter certain herbicides reduce in a linear pattern proportional to the length of time in which wild oats compete with the wheat crop. Therefore maximum yield benefits will be obtained when controlled early as early as possible even though Legislation small yield increases can occur after removal later in
Wild oats are not declared noxious in the the season. Murrumbidgee catchment. Wild oats host a number of cereal pests and diseases Taxonomy including cereal cyst nematode (Heterodera avenae), root lesion nematode (Pratylenchus neglectus and P. Wild oats belong to the Poaceae family along with thornei), rhizoctonia (Rhizoctonia solani) and crown rot wheat (Triticum aestivum), barley (Hordeum vulgare) (Fusarium graminearum). They also host the bacteria and oats (Avena sativa). There are three species of that cause annual ryegrass toxicity (Rathayibacter wild oats in Australia- Avena fatua, Avena ludoviciana toxicus). (also known as Avena sterilis) and Avena barbata. Wild oats tend to grow in patches in a paddock and are Wild oats are also commonly known as black oats and found on most soil types from light to heavy textured bearded oats. They can be confused with Brome soils with a pH range of 4.5-9 (Nugent, Storrie & Medd 1999).
Identification Seed bank
The leaves of wild oat Wild oat seeds are relatively short lived having a half seedlings usually twist in an life of only 6 months. This means 75% of the seed anticlockwise direction as bank can diminish in 12 months and 99% in 2 years in opposed to wheat and barley the absence of new seed inputs (McGillion & Storrie (Figure 2). They have some 2006; Medd 1996). Seedbank decline generally follows hairs on their leaves, a large an exponential pattern with the greatest loss occurring ligule, no auricles and the in the first year (56-81%) (Figure 5) (Nietschke 1997). emerging leaf is rolled as Seeds rarely survive longer than 3 years and research opposed to folded. The has shown that persistent control for 3-5 years can seedlings are blue-green in virtually eradicate wild oats. However due to the prolific colour, especially when seed production of wild oats one season of poor stressed. Mature wild oat control can replenish the seed bank. Soil type also plants are up to 120cm tall. affects the seedbank as seedling recruitment and seedbank decline is greater in sandy soil compared to heavy soils.
Photo: weedman.forsham.net.au Figure 2. Avena fatua seedling 120
Before flowering, it is very difficult to distinguish between the wild oat species. The spikelets of A. fatua 100 (Figure 3) hang from both sides of the floret and from only one side in A. barbata. The spikelet of A. 80 ludoviciana does not break up easily as it does in the other two species. Wild oat seeds can vary in colour from black to yellow and may have gold-brown hairs 60 (Figure 4).
40 Wild oat seed in the soil (%) soil the in seed oat Wild
20
0 0 5 10 15 20 25 Time (months)
Figure 5. Persistence of wild oat seeds in the soil in the absence of seed input (adapted from Storrie et al. n.d.).
Seed dormancy and germination
Seed dormancy is relatively short lived in wild oat seeds that are on or near the soil surface. Dormancy
Photo: Ian Lunt will be greater in buried seeds due to the cool, moist environment and lack of oxygen. Buried seeds may Figure 3. Avena fatua spikelet (Photo Ian Lunt). remain viable in the soil for up to 10 years however once brought to the surface these seeds will be released from dormancy and will germinate readily.
Approximately 40% of the wild oat (A. fatua) seed bank germinates after opening rains and a further 30% later in the season (Nugent, Storrie & Medd 1999). Germination occurs from autumn to spring with the later, smaller cohorts producing enough seed to replenish the seed bank. Wild oats have a large germination window and will germinate in temperatures of 10-26.5°C.
The emergence patterns of the three wild oat species differ slightly although this is unlikely to significantly impact on management. A. fatua germinates from
Photo: Ian Lunt autumn to spring whereas A. ludoviciana germinates in
Figure 4. Avena fatua seed (Photo Ian Lunt). winter to early spring (Medd 1996). A. barbata
predominantly germinates after opening rains (Nugent, infestation can produce 20,000 seeds/m2 (McGillion & Storrie & Medd 1999). Storrie 2006). The number of seeds produced depends on weed density, crop density and vigour, time of The dormancy of wild oat seeds depends somewhat emergence, soil moisture, soil fertility and on the origin of the seeds. Primary seeds of each management. spikelet have been found to germinate in a single cohort following opening rains whereas secondary Most seeds of wild oats fall within one metre of the seeds are more persistent and therefore have parent plant. Long distance spread commonly occurs protracted germination (Cousens 2003). in fodder and grain, by livestock (e.g. on their coats) and on machinery. Delaying harvest until more seed Flowering has shed from the parent plant may reduce the dispersal of mature seeds by harvesters. The wild oat panicle is spreading and open, up to 40cm long and 20cm wide, and occurs on both sides of the stem (except in A. barbata). The large spikelets MANAGEMENT have 2-3 flowers (2-5 in A. ludoviciana) and the florets fall as single seeds when mature. A.ludoviciana The physiology of wild oats (staggered germination, flowers slightly earlier than A.fatua however the prolific seed production, self-pollination, high implications for management are likely to be competitiveness, rapid maturity and early seed shed) insignificant. together with widespread herbicide resistance makes their control difficult. It is essential to use an integrated Seed production and dispersal weed management (IWM) approach utilising a wide range of chemical, cultural and biological control Wild oats are self-pollinated so reproduction can occur options (Table 1). from a single plant. They are prolific seed producers and one plant can produce 225 seeds and an
Table 1. Weed control tactics and their expected control for wild oats (Avena spp.) (McGillion & Storrie 2006).
Tactic Likely control (%) (and control range) Crop choice and sequence 95 (30-99) Improve crop competition 70 (20-99) Herbicide tolerant crops 90 (80-99) Autumn tickle 40 (30-60) Knockdown pre-sowing (non-selective herbicide) 80 (70-90) Pre-emergent herbicides 80 (70-90) Selective post-emergent herbicides 80 (70-90) Spray-topping (selective herbicide) 90 (60-99) Pasture spray-topping 80 (70-90) Cutting for hay and silage 97 (95-99) Grazing 75 (60-80) Weed seed collection at harvest 70 (20-80)
Reproduction rather than seed carryover is the main Integrated weed management programs should be mechanism of persistence in wild oat populations. based on long-term considerations including seed Management programs should aim to prevent seed production and the possibility of herbicide resistance production and seedbank inputs every year while developing. Jones, Cacho and Sinden (2003) minimising reductions in grain yield and quality. concluded that there are significant potential economic Infestations should be controlled as early as possible benefits associated with long term integrated weed after emergence as wild oats do most damage due to management systems for the control of wild oats and in competition early in the growing season (Table 2). particular the inclusion of increased crop competition, selective spray topping and crop and pasture rotations.
Table 2. Approximate yield responses from wild oat control in wheat and barley (Adapted from Anderson 2003).
Percent Yield Response from Weed Control Wild Oat Density Pre-tillering Early Tillering Mid-tillering 50 Plant/m2 17 15 12 100 Plant/m2 26 23 17 200 Plant/m2 36 32 22 300 Plant/m2 42 36 25
Chemical Options
New herbicide Mode of Action Groups
Following a review of current herbicide mode of action groups by CropLife Australia in 2007, several herbicides have been allocated to new groups (Table 3). The purpose of this is to improve the accuracy of mode of action groupings to enable more informed decisions regarding herbicide rotations and resistance management. Two key herbicides for the control of wild oats, Mataven® and Avadex®, have been reclassified. Manufacturers have three years to update labels however the new groups should be used when making resistance management decisions from now. Here, the new mode of action groups will be given following the old groups, e.g. Mataven® is a Group K (Group Z) herbicide.
Table 3. Changes to herbicide mode of action groups (valid as at 28th February 2008) (CropLife Australia 2008).
Active Constituent Product Trade Name Chemical Family Old MOA Group New MOA Group Amitrole Smitrole®, Illico® Triazoles F Q Asulam Asulox® Carbamates K R Bensulide Prefar® Phosphorodithioates E J Benzofenap Taipan®, Viper® Pyrazoles F H Clomazone Command®, Viper® Isoxazolidinones F Q Dichlobenil Casoron® Nitriles K O DSMA DSMA®, Methar® Organoarsenicals K Z MSMA Daconate® Organoarsenicals K Z Endothal Endothal® Dicarboxylic acids K Z EPTC Eptam® Thiocarbamates E J Ethofumesate Tramat® Benzofurans K J Flamprop Mataven® Arylaminopropionic acids K Z Isoxaben Gallery® Benzamides K O Isoxaflutole Balance® Isoxazoles F H Molinate Ordram® Thiocarbamates E J Naptalam Alanap-L® Phthalamates K P Pebulate Tillam® Thiocarbamates E J Phenmedipham Betanal® Phenylcarbamates K C Propyzamide Kerb® Benzamides K D Thiobencarb Saturn® Thiocarbamates E J Triallate Avadex® Thiocarbamates E J Vernolate Vernam® Thiocarbamates E J
There are a number of herbicides available for the populations are resistant to the Group K (Group Z) control of wild oats in crops. Although these can herbicide Mataven® and at least 2 to Group B significantly reduce wild oat populations, when used herbicides (Widderick & Walker 2007). The control of alone they often fail to give satisfactory control of seed wild oats by the Group B herbicide Hussar® has set due to the staggered germination pattern (Nugent, declined after only 3 applications in areas with a history Storrie & Medd 1999). In addition, several herbicides of Group B herbicide use (Widderick & Walker 2006). are no longer effective on wild oats due to the development of herbicide resistance. The majority of wild oat populations in New South Wales resistant to Group K (Group Z) herbicides are The first case of wild oat resistance was to the Group also resistant to Group A ‘fop’ herbicides (Broster A herbicides in Western Australia in 1985 followed by 2007), and possibly Group B (Widderick & Walker South Australia and New South Wales to the same 2007). Some populations with resistance to Group A herbicide group in 1991 (Heap 2008). Since then the herbicides are also resistance to Group K (Group Z) incidence has increased dramatically and steadily. In herbicides even though they have never been exposed 2003, a random survey conducted in northern New to Group K (Group Z) (Storrie 2007). South Wales and southern Queensland reported that 10% of all wild oat populations were resistant to Group A variety of pre and post-emergent herbicides should A herbicides (Widderick & Walker 2007). Wild oat be used and herbicide mode of action groups should populations that have had more than 6 applications of be rotated to delay the onset of herbicide resistance if it a Group A herbicide over the last 15 years are at a has not already occurred. Only one application of a high risk of developing resistance to these herbicides Group A herbicide should be made per season and (Storrie 2007). Group A should not be used if it was used the previous year (Anderson 2003). No more than 1 Group B Resistance to the Group K (Group Z) herbicide herbicide should be applied to the same crop in one flamprop-methyl (Mataven®) was recorded in 2002 year and a maximum of 2 Group B herbicides should and to Group B herbicides in 2005 (McGillion & Storrie be applied in a four year period (Anderson 2003). 2006). In New South Wales alone, at least 9
Survivors of herbicide applications should be tested emergent herbicides because wild oats which emerge for resistance and controlled by an alternative method at the same time as the crop cause the greatest yield to prevent seed set. If you see survivors, collect a loss (Nietschke & Medd 1996). Although the pre- sample to be tested by a herbicide resistance testing emergent herbicides trifluralin (Group D) and Avadex® service and employ strategies to prevent weed seed (Group E (Group J)) can significantly reduce the wild set. Contact the Charles Sturt University Herbicide oat population, survivors have been found to produce Testing Service on (02) 6933 4001. up to 1200 seeds/m2 therefore pre-emergent herbicides need to be used in conjunction with other Pre-emergent herbicides for the control of wild oats control techniques (Table 4) (Widderick & Walker have been found to be more profitable than post- 2007).
Table 4. An example of a herbicide resistant wild oat population management strategy (adapted from Johnson et al. 2006).
Year Technique/Comment Wild oat resistance to Group A confirmed 2002 Wheat crop topped with Mataven® (Group K (Group Z)) which gave excellent results Harvester was thoroughly cleaned after harvesting infested paddock to prevent spread. Wild oats heavily grazed by sheep following emergence. 2003 Paddock sprayed with glyphosate (Group M) in July. Paddock sprayed a second time with glyphosate (Group M) in September. Lucerne and medic pasture sown in autumn. 2004 Lucerne spray-topped with Gramoxone® (Group L) in spring. 2005 Low density of wild oats in lucerne spray-topped. Maintain competitive pasture. 2006 Continuous monitoring of any wild oat germinations.
The double knock strategy where survivors of one Crop-topping (the application of non-selective technique are controlled by an alternative method or herbicides to the crop at the beginning of seed set) can herbicide is particularly valuable where resistance to reduce the wild oat seedbank by 53% the following selective herbicides is known. For example, year (Nugent, Storrie & Medd 1999). glyphosate followed by paraquat 2 days later or a pre- emergent herbicide followed by selective spray- Spray-topping in pastures (sub-lethal doses of non- topping can reduce the seedbank by 99% over 5 years selective herbicides) can prevent wild oat seed (Newman & Storrie 2007). formation and assist in significantly depleting the wild oat seed bank before the cropping phase. Spray- Selective spray-topping (the late post-emergent topping should follow heavy grazing which encourages application of selective herbicides) can reduce wild oat the seed heads to emerge at the same time. Annual seed production by up to 97% provided there is no applications of glyphosate have been found to reduce resistance to Group K (Group Z) herbicides (Nietschke the wild oat seed bank by 97% in three and a half & Medd 1996). This method should only be used to years (Nietschke & Medd 1996). Winter cleaning in control seed set of survivors of earlier treatments or pastures with selective herbicides to kill all grass later emerging cohorts as it is not effective for high weeds can also significantly reduce the seed set of wild oat densities (greater than 50 plants/m2). wild oats. Mataven® is the only current herbicide for spray- topping so this technique should only be used Cultural Options periodically. Competitive crop and pasture species The major benefit of selective spray-topping is seen in the following years through seed bank decline Crop competitiveness with wild oats can be increased however crop yield can increase by up to 10% in the by high seeding rates, good quality seed, competitive year of application (Nugent, Storrie & Medd 1999). crop species and varieties, narrow row spacing, correct The timing of herbicide application is important and sowing depth, optimum fertiliser regimes and ensuring best control (97%) is obtained when Mataven® is the crop is free from other constraints (e.g. disease). applied at the early tillering stage of the crop Research has shown that increasing crop density from 2 2 (Nietschke 1997). It must be done before the flag leaf 50 plants/m to 100 plants/m can reduce wild oat seed 2 emerges for good control and reduced risk of crop production from 550 to 230 seeds/m (58%) in wheat 2 damage. Please note that some wheat varieties are and from 21 to 7 seeds/m (67%) in barley (Walker, sensitive to Mataven® (refer to the latest version of Robinson & Medd 1998). Barley is most competitive ‘Weed Control in Winter Crops’ available from NSW with wild oats followed by (in descending order) wheat, Department of Primary Industries). canola, oats, faba beans, peas, chickpeas/lentils/lupins (Nugent, Storrie & Medd 1999).
Hygiene Hay and silage making and green manuring
Poor farm hygiene can facilitate the introduction, Cutting crops or pastures for hay or silage and green spread and persistence of wild oats. Machinery and manuring are effective methods for preventing weed equipment should be cleaned when moving between seed set providing regrowth is controlled and it is cut paddocks and, if possible, harvest clean paddocks before the wild oats begin to shed seeds. Wild oat first, cover grain loads, use only clean seed (always emergence has been reduced to nil after three check the certificate and be aware that certified seed consecutive years of cutting for silage (Nietschke may still contain small amounts of wild oat seeds) and 1996). These techniques are particularly valuable in feed hay or silage out in specified areas (especially if paddocks that contain herbicide resistant weed brought in) as it may contain herbicide resistant wild populations. oat seeds. Crop and pasture rotation Cultivation Martin and Felton (1993) concluded that the most Wild oat seed banks decline more rapidly in minimum effective way of reducing wild oat seedbanks was crop and no-till systems than conventional cultivation and pasture rotation (compared to tillage and herbicide (Nugent, Storrie & Medd 1999; McGillion & Storrie strategies). Alternative crops and pastures enable the 2006). This is due to most seeds remaining on the soil use of other control methods such as grazing, slashing, surface where they decay faster due to constant hay making and herbicides with different modes of changes in temperature, moisture and light, and can action. Weed control may also be cheaper in some be destroyed by predators. Cultivation buries seeds phases of the rotation, such as in pastures, compared promoting seed longevity and extending the life of the to crops. seedbank by inducing dormancy however the seeds will become germinable when brought to the surface in Incorporating a pasture phase can prevent seed set of subsequent tillage operations (Widderick & Walker wild oats and significantly reduce the seedbank for the 2007; Nietschke 1996). cropping phase (Nietschke 1996). Continuous cropping systems favour wild oats and are unlikely to reduce Delayed seeding wild oats seedbanks to an acceptable level (Johnson et al. 2006). Martin & Felton (1993) showed that 4 Delaying crop seeding to control the first cohort of successive wheat crops with annual applications of weed seedlings prior to sowing is less effective with either tri-allate (Avadex® Xtra) or flamprop-methyl wild oats than other weed species due to its staggered (Mataven®) did not prevent wild oat seed build-up. germination pattern and is generally not considered an economic control method (Nugent, Storrie & Medd Herbicide tolerant crops 1995; Nietschke 1996). Although it may be beneficial to sow paddocks with known wild oat infestations last, Clearfield® cropping systems provide an alternative care should be taken to avoid reductions in grain yield option for the control of several hard to kill weeds and quality as a result of later sowing. including wild oats. Clearfield wheat varieties (non- GMO) are tolerant to the imidazolinone herbicide Fertiliser Midas® (Group B) registered for the control of wild oats in wheat. A combination of trifluralin and Midas® Wild oats compete strongly with crops for nutrients. sprayed 4 weeks after emergence of wheat controlled Banding nitrogen near the crop rows is preferable to 80% of wild oats compared with only 50% control for broadcasting as the crop will access it before the wild trifluralin and Monza® (Hashem 2005). Triazine oats giving a competitive advantage to crop plants. tolerant (TT) canola allows the use of atrazine and simazine (Group C) which are registered for the Seed collection suppression of wild oats.
Catching wild oat seeds at harvest time is generally ineffective due to the high proportion of seeds shed Grazing prior to harvest. Wild oats are palatable to stock and may provide a valuable feed source in pastures. Sheep will eat wild Stubble burning oat seeds directly off the plant, especially when they’re
Stubble burning can reduce viable wild oat seeds on at the soft dough stage of development. Stocking rates the soil surface by up to 98% however it will also need to be high and regrowth needs to be controlled stimulate germination of the remaining seeds when grazing is used as a weed control tactic. increasing emergence in burnt areas (Nietschke 1997). These may then be controlled with a Allelopathy knockdown herbicide. Stubble burning must be used Some crop stubbles have the ability to reduce the judiciously and in conjunction with other weed control emergence and growth of wild oats however it is strategies due to the increased risk of erosion variable (Nietschke 1996). Jones et al. (1999) found following burning. that barley stubble was the most effective at reducing wild oat emergence followed by canola and then chickpeas. Conversely, sorghum and wheat may have
a stimulatory effect increasing germination and BIOLOGICAL OPTIONS emergence of wild oats (Jones et al 1999; Pratley 1996). Ants are widespread in cropping regions and several species play a major role in removing weed seeds from Wild oat stubble may also have an allelopathic effect the system. They are more effective in no-till systems on subsequent wheat crops. Exudates from wild oat and under low to moderate stubble loads. roots have been found to reduce the growth of wheat roots and shoots (Kirby 2000). Several pathogens have been identified, isolated and shown to infect wild oats however none are currently available for use as biological control agents (Hetherington & Auld 1996).
References
Anderson, C. (2003) Operation Wild Oats, Bayer CropScience. McGillion, T. & Storrie, A. (eds). (2006) Integrated weed management Available at in Australian cropping systems- A training resource for farm advisors. http://www.bayercropscience.com.au/xml/data/brochure/attachment CRC for Australian Weed Management, Adelaide, South Australia. s/Operation%20Wildoats%20Strategy%20Guide.pdf. Medd, R.W. (1996) ‘Ecology of wild oats’, Plant Protection Quarterly, Broster, J. (2007) Charles Sturt University 2007 Herbicide Vol.11 Supplement 1, pp185-187. Resistance Testing Service Report, Charles Sturt University, Wagga Wagga, New South Wales. Newman, P. & Storrie, A. (2007) ‘Don’t knock out your options’, Ground Cover Issue 68, Grains Research and Development Heap I. (2008) ‘Group A/1 Resistant wild oat (Avena fatua)’, Corporation. WeedScience.com- International survey of herbicide resistant weeds. Available at Nietschke, B.S. (1996) ‘Cultural weed management of wild oats’, http://www.weedscience.org/Case/Case.asp?ResistID=5. Plant Protection Quarterly, Vol. 11 Supplement 1, pp. 187-189.
Cousens, R. (2003) ‘Significance of mixed infestations of wild oat Nietschke, B.S. (1997) ‘Integrates strategies for wild oat (Avena spp.) species for integrates management’, GRDC Research Summary, management in southern Australian farming systems’, PhD thesis, Grains Research and Development Corporation. Available at The University of Adelaide, Roseworthy, South Australia. http://www.grdc.com.au/director/events/researchupdates. Nietschke, B.S. & Medd, R.W. (1996) ‘Chemical weed management CropLife Australia (2008) ‘Herbicide Resistance Management of wild oats’, Plant Protection Quarterly, Vol.11 Supplement 1, pp. Strategies’, CropLife Australia. Available at 190-192. www.croplifeaustralia.org.au. Nugent, T., Storrie, A. & Medd, R. (1999) Managing Wild Oats. CRC Hashem, A. (2005) ‘Utilising Clearfield and eagle Rock wheat for Weed Management Systems and Grains Research and varieties to manage hard to kill grass weeds’, WANTFA, Department Development Corporation. of Agriculture and Food, Western Australia. Pratley, J.E. (1996) ‘Allelopathy in annual grasses’, Plant Protection Hetherington, S.D. & Auld, B.A. (1996) ‘Biological control of annual Quarterly, Vol.11 Supplement 1, pp. 213-214. grass weeds – progress and prospects’, Plant Protection Quarterly, Vol.11 Supplement 1, pp. 215-216. Storrie, A. (2007) ‘Wild oat resistance options’, Grains Research Update- Northern region, Grains Research & Development Johnson, A., Brooke, G., Thompson, R., Roberts, K., Hertel, K., Corporation. Available at Border, N., McNee, T. & Sullivan, P. (2006) Weed control for http://users.tpg.com.au/icanadsl/newsletters/NL37V4.pdf. cropping and pastures in central west NSW, NSW Department of Primary Industries. Available at Storrie, A., Cook, T., Moylan, P., Maguire, A., Walker, S. & Widderick, http://www.dpi.nsw.gov.au/agriculture/pests- M. (n.d.) ‘Managing herbicide Resistance in Northern New South weeds/weeds/publications/management/central-west. Wales’. Available at http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/155148/herbici Jones, E., Jessop, R.S., Sindel, B.M. & Hoult, A. (1999) ‘Utilising de-resistance-brochure.pdf. crop residues to control weeds’, School of Rural Science and Walker, S.R., Robinson, G.R. & Medd, R.W. (1998) ‘Management of Natural Resources, University of New England, Armidale. wild oats and paradoxa grass with reduced dependence on herbicides’, Proceedings of the Australian Agronomy Conference, Jones, R., Cacho, O. & Sinden, J. (2003) ‘Modelling the dynamics of Australian Society of Agronomy. weed management technologies’, Proceedings of the 47th Annual Conference of the Australian Agricultural and Resource Economic Widderick, M. & Walker, S. (eds.) (2006) The Northern Herbicide society, Fremantle, Western Australia. Resistance Reporter (June 2006). Available at http://www.dpi.nsw.gov.au/agriculture/pests- Kirby, T. (2000) ‘Avena spp.’, Weed ID/Management. Online, weeds/weeds/publications/newsletters/nhrr. available at www.weedman.horsham.net.au. Widderick, M. & Walker, S. (eds.) (2007) The Northern Herbicide Martin, R.J. & Felton, W.L. (1993) ‘Effect of crop rotation, tillage Resistance Reporter (April 2007). Available at practice, and herbicides on the population dynamic of wild oats in http://www.dpi.nsw.gov.au/agriculture/pests- wheat’, Australian Journal of Experimental Agriculture, Vol. 33, pp. weeds/weeds/publications/newsletters/nhrr. 159-165.
Further Information: www.murrumbidgee.cma.nsw.gov.au or www.dpi.nsw.gov.au
Disclaimer
The information contained in this publication is based on knowledge and understanding at the time of writing (2008). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of New South Wales Department of Primary Industries/Murrumbidgee Catchment Management Authority or the user’s independent adviser.
The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a product name does not imply endorsement by NSW Department of Primary Industries or Murrumbidgee CMA over any equivalent product from another manufacturer.
ALWAYS READ THE LABEL Users of agricultural chemical products must always read the label and any Permit, before using the product, and strictly comply with directions on the label and the conditions of any Permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or omitted to be made in this publication.
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